Control method and system for knitting machines



R. BASSIST April 6, 1954 CONTROL METHOD AND SYSTEM FOR KNITTING MACHINES Filed June 14, 1950 INVENTOR. Rudolpkfiagssf.

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Patented Apr. 6, 1954 CONTROL METHOD AND SYSTEM FOR KNITTING MACHINES Rudolph Bassist, Long Island City, N. Y.

Application June 14, 1950, Serial No. 168,065

9 Claims. 1

This invention relates broadly to the method of and a system for producing textile fabric of a superior quality and characterized by the uniformity and evenness Of its structure, especially in knitted fabric, and which method and system consists of correlating and governing the operation of diiferent mechanisms in textile-producing machines, including knitting machines, and. particularly in what is known as high-speed warp knitting machines, for the purpose of balancing the supply and demand of yarn by such machines.

Introduction Knitting machines usually have one or several warp beams about which yarn is wound. The yarn is drawn off from the warp beams to a bank of needles removably mounted in a suitable needle bar, which is adapted to reciprocate in vertical direction at predetermined, intermittent sequences. The operation of the needle bar is induced by cam action.

Each of the yarn threads drawn from the beam or beams passes through a loop provided in individual guide elements supported by a guide bar, the latter being adapted for a combination forward, rearward and a reciprocating transverse movement, all in respect to the needles, whereby the threads are wound about the needles as the latter are caused to reciprocate in vertical direction. The forward and rearward movements of the guide bar are produced by cam actions, whereas the transverse movements thereof are induced by a pattern-producing instrumentality, such as a pattern wheel or its equivalent. The length of that transverse movement may be varied according to the stitch length desired.

The cams for reciprocating the needle bar in an up-and-down movement, and the cams for operating the guide bar in forward-backward directions are mounted upon a main or cam shaft of the warp knitting machine. That shaft is usually driven by a motor and carries additional cams or other actuating means for operating auxiliary knitting machine mechanisms, required in the production of knitted fabrics, such as a presser bar, adapted to engage the "spring heard of the normally open semi-loop or crook at the upper needle end during the downward movement of the needles to close that crook and entrap yarn held therein for passage through a previously completed yarn loop; or the sinker bar, carrying a series of sinkers adapted for successively tightening the formed yarn loops, and. lifting them from the needles over their closed spring beard end.

The warp beam or beams are driven from the cam shaft by way of a controlled speed changer, a speed reducer and the required transmission elements. The cam shaft also actuates a pattern mechanism, such as a pattern wheel, which governs the operation of the guide bar and its yarnguide elements relative to the needles in con-' formity with the desired pattern of the fabric to be produced.

The quality of knitted fabric is determined by a variety of factors, some of which bein the uniformity and evenness of the fabric, and the absence of what is known as faults occurring during the knitting operation in conventional types of warp knitting machines. Such defects in the quality of knitted fabrics become accentuated in knitting machines of the fine gauge Tricot type machines using, say, 28 to 32 needles per inch, and operating at substantially high speeds, say of between 350 to 450 courses or stitches per minute, unless proper ways and means are provided to obviate such faults.

The uniformity and evenness of a knitted fabric largely depends upon several conditions, one of them being the relation between thelength of yarn required for a specific number of stitches to be produced, another is the relation of the yarn speed to the length variations of stitches and the consequent varying demand for yarn, determined by the pattern desired, a third condition is the tension of the yarn between the warp beam and the needles, and finally, the fourth condition is the type of fabric desired and the pattern or design of such fabric.

The present invention contemplates the elimination of faults in knitted fabric and the production of fabric of a superior quality, and which is uniform and even in its structure throughout the entire run from the machine producing it, including its patterns formed by different groups or periods of varying stitch lengths. In order to achieve these advantages it is essential to accurately and automatically synchronize the yarn feed with the combined yarn demand by the needles and the pattern-producing means, which latter governs the length of the stitches. I Although the present invention is primarily intended for application to single or multiple warp knitting machines, and particularly to the Tricot type, high-speed and high-gauge machines, the principle of this invention may be most advantageously adapted to many other types of knitting machines for controlling the yarn feed in relation to the needle and patternforming operations.

The prime objects'of this invention, therefore,

are the method of and the system for automatically correlating the yarn feed with the yarn demand for the stitch-producing operations.

Another object is the provision of means for automatically governing the speed at which the warp beam or warp beams operate in relation to the speed of operation of the needles, or vice versa, and the provision of means for automati cally correlating the yarn feed with the yarn demand for knitting operations by the needles for the production of stitches of either uniform or even length, or stitches or stitch periods of varying length.

A more specific object of the present invention is the provision of a control system responsive to both the speed of operation of the cam shaft actuating the needles and the pattern-producing instrumentality on one hand, and to the linear speed of the yarn fed to or drawn by the stitchproducing mechanisms on the other hand, and which system contains suitable means for automatically controlling and governing the rate of yarn delivered to the needles.

The foregoing and a number of other important objects and advantages of the present invention will become more fully disclosed and understood from the following description of the accompanying drawings, held in a purely diagrammatical form, and being intended to facilitate the elucidation of the principle of this disclosure, without in any way limiting the latter to the actual showing, and in which drawings:

Fig. 1 is a diagram of a system for correlating yarn feed with the number of stitches made by the needles, in accordance with the present invention;

Fig. 2 is an end elevation of the speed changer used in the system;

Fig. 3 is a fragmental diagrammatical detail view of the guide bar and of the instrumentality for operating it in forward and backward directions; and

Fig. 4 is a fragmental diagrammatical detail view of the needle bar and of its actuating mechanism for reciprocating it in upward and downward directions.

In the drawings numeral I denotes the framework of a warp knitting machine which supports the main or cam shaft I I as well as needle bar !2, guide bar I3 and warp beam I4.

In addition to the above main instrumentalities of the knitting machine, the frame also is intended to support the presser bar, the sinker bar, both not shown, and a pattern wheel i5, operated by means of worm gear I8 and worm H, the latter being keyed to shaft ii. Furthermore the framework also supports additional devices such as the speed changer It, speed reducer I9, and such other instrumentalities which form parts of the present system, as will be explained presently.

Cam shaft I I is driven by a motor 25 and chain transmission 2 I and warp beam I 4 is driven from shaft I I by transmission element 22, speed changer I8, transmission element 23, speed reducer I9 and transmission element 254. The speed reducer and speed changer it are of conventional designs.

The speed changer is adapted to be automatically actuated by means of pinion 25 and gear rack 26, which latter is designed to move in either of the two directions indicated by double arrow "I."

Gear rack 26 is moved in left-hand or positive direction by the arrangement of ratchet wheel 21, ratchet pawl 28 and pawl-operating arm 29,

the latter being actuated by bar 30 through solenoid 3L. A negative or right-hand movement of the rack is being imparted thereto by a similar ratchet wheel 32, a pawl 33, a pawl-operating arm 3% and an actuating bar 35, which latter is operated by solenoid 36. The movement of pawl arms 29 and 34 can be limited by the adjustment of set screws 21 and 32', respectively. Pawloperating arms 29 and 3c are normally drawn toward their respective set screws by springs 2i" and E2 Ratchet wheels 21 and 32 are mounted on shaft 31, and keyed to that shaft is gear 33 in engagement with gear rack 23. Pawls 23 and 33 may be disengaged from their respective ratchet wheels 2? and 32 by the armatures of solenoids 28' and 33', when the latter become energized. These solenoids are supported by extensions 25 and 3 of the pawl arms 23 and 34, respectively.

Driven by cam shaft/II through the medium of transmission elements 39 and ti! are predetermining and pro-settztble counters ll and 62. Counter H computes the revolutions of cam shaft I I or the number of stitches made by the needles and is called primary or stitch or just revolution counter. Counter 42 is called a re-setting or secondary revolution counter, being also responsive to the revolutions of shaft I I.

In engagement with and actuated by the linear run-off of the yarn from warp beam Isl there will be observed a third counter 33, called the yarn length measuring or linear counter, which is adapted to register the yarn fed to the needles in length measurements. Also this counter is a predetermining and presettable counter.

Predetermined counters have two groups of wheels, one group being operated by the usual computing action of the counters, while the other group is known as the predetermining wheels, which are pre-set by hand to any number desired. Each time the counter shaft completes the desired number of turns to which the predetermining wheels are set, a switch is operated.

Revolution counter 4|, re-setting counter t2 and linear counter 43 are provided with normally open switches 41, 42' and 43', respectively.

hi the electric portion of the diagram are indicated two differential relays 4d and 55, the left ends 46 and 41 of which are connected, respectively, to revolution counter 4i and linear counter 43, while the right-hand ends 48 and ll} of the relays are both connected with re-setting counter 42, which latter is a control device adapted to restore relays M and 45 to their normal position each time cam shaft I! completes a predetermined number of revolutions, to which the predetermining wheels of re-setting counter 42 are set.

In conjunction with solenoid-actuated bars 39 and 35 there will be observed two switch assemblies, broadly indicated, respectively, at to and 5%, adapted for operation by detents 52 and 53 se cured to bars 39 and 35, respectively. These switch assemblies, termed lower and upper for quick identification, diagrammatically illustrate spring-loaded levers E i and 55 connected with switches 56 and 57, respectively, which are kept normally closed by springs 54' and 55 of the levers.

Electric connections Current is supplied to the various electric circuits by main conductors 58 and 59. The lowermost branch 53' of conductor 58 is connected to one terminal of the normally open switch M of revolution counter 51, and from its other termi- "'nal lead 60 passes tothe left end relay part '46 of the lower differential relay'44. From relay part 43 lead 6| extends to normally closed switch 57 of the upper switch assembly 5|, and from switch 51 lead 32 connects with main conductor 59. Thus the circuit for energizing left relay part 46 by the closing of switch 4| of revolution counter 4| is kept normally ready for action as long as switch 5! is in its normal, closed position.

Switch 43 of linear counter 43 controls the circuit for energizing left relay part 41 of the upper differential relay 45. From one of the switch terminals lead 63 extends to one terminal of switch 56 of the lower switch assembly 53. The other terminal of switch 56 is connected by lead 64 to one terminal of left relay part 41, while the latters other terminal is connected by leads 35 and 66 to main conductor 59. The second terminal of counter switch 43' is connected by leads 6! and 68 to main conductor 58.

The closing of switch 42' of re-setting or control counter 42 energizes simultaneously the right ends 48 and 49 of lower and upper diiferen tial relays 44 and 45. One terminal of switch 42' is connected by lead 69 to main conductor 59. From its other terminal extend leads E and 7| to one terminal of right relay end 43 of the lower relay 44. The other terminal of relay end 48 is connected by leads 12 and 13 to main conductor 58. Branching off from leads l0 and 73 are conductors l4 and 15 which extend to the terminals of right end relay part 49 of the upper differential relay 45. Y 7

Solenoids 3| and 36 become energized when the switches of differential relays 44 and 45 are closed. One terminal of solenoid 3| is directly connected by lead it, normally closed, springloaded switch 15 and lead H to main conductor 59, while from its other terminal lead 18 extends to one terminal of switch 19 of relay 44. The other switch terminal 83 is connected by lead 8| to main conductor 58. Connected with leads l and 18 extending from the terminals of solenoid 3| are leads BI and 82 which pass to pawlreleasing solenoid 33. Solenoid 3| and pawlreleasing solenoid 33' become energized simultaneously when the switch of lower relay 44 is closed by the closing of revolution counter switch 4| The left terminal of solenoid 33 is connected by lead 83, the normally closed, spring-loaded switch 83' and lead 63 to main conductor 59; its other terminal is connected by lead 34 to switch terminal 85 of upper relay 45. The second switch terminal 33 is connected through lead 33 to main conductor 58. From leads 83 and 84 of the left and right terminals of solenoid 36 extend leads 8'! and 38 to lower pawl-releasing solenoid 23. When the switch of the upper differential relay 45 is closed by the closing of switch 43 of linear counter 43, both solenoid 33 and pawl-releasing solenoid 28' become simultaneously energized.

Operation 7 f ance with the amount of the required yarn.

Each revolution of cam shaft constitutes one stitching operation by the needles. evolution counter 4| is set so, for instance, that'after each '1,000' revolutions of the cam shaft switch 4| of the counter becomes momentarily closed.

Linear counter .43 measures the length of the yarn delivery from the warp beam I4 to the needles, and is set so that for each inches of yarn the counter will close switch 43'. Thus when the closing of switch 4| of revolution counter 4| and of switch 43 of linear counter 43 coincide with one another, the yarn delivery and the stitch number are balanced, that is, warp beam M has delivered the required 120 inches of yarn, while the needles have completed the required 1,000 stitches. As a result of maintaining that balance, the produced knitted goods will be completely even and uniform throughout their entire structure. In other words, the knitted loops in the fabric formed by the needles and by the auxiliary mechanisms co-acting with the needles, will be of the proper or desired quality; they will be neither too tight nor too loose, or too large or too small, but uniform in size and structure, as long as the exact amount of yarn delivered for an exact number of stitches is kept constant as well as is mechanically possible. The following paragraphs will explain the method of constantly maintaining the yarn feed in balance with or in correct proportion to the stitch number.

Insufiiciency of yarn delivery Assuming that an insufiicient amount of yarn is being delivered to the needles for the required 1,000 stitches. Upon completion of each 1,000 stitches, revolution counter 4| actuates switch 4| and closes the circuit of left relay portion 46 of lower differential relay 44, whereby solenoid 3| becomes energized and pulls in bar 39. That operation of the bar will cause ratchet pawl 28 to move ratchet wheel 27 in clockwise or plus direction, which in turn will rotate shaft 31 and gear 39, thereby moving gear rack 26 to the left. The latter will cause pinion 25 of the speed changer I8 to revolve clockwise, thereby increasing the speed of warp beam l4, to deliver yarn to the needles at a faster rate.

As bar 39 is drawn in by solenoid 3|, detent 52 engages lever 54, moving it to the left, thereby opening switch 56 of lower switch assembly 50, thus rendering the circuit controlled by linear counter switch 43 inoperative. In other words, if linear counter 43 should close its switch 43', due to the passage from warp beam 4 of 120 inches of yarn, left relay part 41 of upper relay 45 can not be energized.

When solenoid 3| becomes energized by the closing of revolution counter switch 4|, pawlreleasing solenoid 33 of upper ratchet wheel 34 becomes also energized and lifts the pawl 33 out of engagement with the teeth of wheel 34, thus permitting shaft 31 to rotate in clockwise direction.

As bar 30 completes its movement, induced by energized solenoid 3!, its left protruding insulated end opens the normally closed switch 16', thus cutting off current to the solenoid and deenergizing it. Meantime revolution counter 4| has completed a sufiicient number of turns to permit its switch 4| to reassume its normal, open position, thereby de-energizing left relay end 45 of the lower differential relay 44.

Re-setting counter 42 is adjusted to momentarily close its switch 42' several revolutions after counter 4| has closed its switch 4|. The closing of switch 42 simultaneously energizes the circuits of right end relay parts '43 and. 49,

of lower and upper differential. relays 44 and 45, respectively, which causes the re-setting or opening of the relay switches preparatory to the next action by either the revolution counter switch 4| or by the linear counter switch 42'.

At the moment solenoid 3| is de-energized, bar 33 is free to be moved by spring 21", engaging pawl arm 21, to its normal, inoperative position indicated. During its movement to that position, detent 52 of bar releases lever 54, thereby causing spring 54' to close switch 56, thus completing the circuit controlled by linear counter switch 43'.

While solenoid 3| becomes d e-energized, also the upper pawl-releasing solenoid 33' is de-energized and permits pawl 33 to re-engage the teeth of ratchet wheel 32.

Yarn feed exceeds requirement Assume that linear counter 43 operates to close its switch 43' before revolution counter 4| operates to close its switch 4|. That condition indicates that a surplus delivery of yarn to the eedles is taking place, which would cause longer or looser loops being formed in the knitted goods.

The closing of linear counter switch 43 energizes the circuit of left-hand relay portion 41 in upper differential relay 45. As a result the relay switch is closed and solenoid 36 becomes energized and draws in bar 35, thereby causing pawl 33 to move ratchet wheel 32 in anti-clockwise or negative direction. Consequently shaft 31 turns gear 38 in the same direction, whereupon gear rack 25 is propelled to the right or in negative direction and causes gear 25 to rotate in anti-clockwise direction. That movement of gear 25 operates speed changer l8 to slow down the speed of warp beam i4, thereby reducing the yarn feed to the needles.

When solenoid 36 is energized, lower pawlreleasing solenoid 28 becomes energized also and lifts pawl 28 out of engagement with the teeth of ratchet wheel 29, thereby facilitating the latters rotation in anti-clockwise direction.

At the moment bar is drawn in by solenoid 35, detent 53 engages spring-loaded lever 55 and causes it to travel toward the solenoid, thereby opening switch 51, thus de-energizing the circuit controlled by revolution counter switch 4|, and rendering solenoid 3| inoperative. In other words, in the event revolution counter 4| should close its switch 4|, the left end 45 of lower relay 44 can not become energized; the switch of the lower relay remains open and solenoid 3; remains de-energized.

The movement of bar 35 induced by energized solenoid 35 causes pawl arm 34 and pawl 33 to turn ratchet wheel 32 in anti-clockwise or negative direction. Consequently shaft 31 and gear 38 move in the same direction and cause gear rack 26 to shift to the right or in minus direction, whereby pinion 25 is rotated in anti-clockwise direction and causes speed changer I8 to reduce the speed of warp beam l4. As a result the feed of yarn from the beam is reduced.

As bar 35 is drawn in by upper solenoid 36, its left protruding insulated end opens the normally closed, spring-loaded holding switch 83', whereby the circuit of solenoid 35 becomes deenergized, and bar 35 is free to be moved to its normal, illustrated position by spring 52 engaging pawl-operating arm 34. At the same time lower pawl-releasing solenoid 25' becomes de-energ'med and permits pawl 25 to re-engage the teeth or lower ratchet wheel 29.

During the movement of bar 35 to its normal position, detent 53 releases lever 55, and the latters spring 55' causes the closing of switch 51 and renders the circuit controlled by revolution counter switch 4| operative.

Meantime linear counter 45 has completed a few turns to open its switch 43, thereby deenergizing left part 41 of the upper differential relay 45. Also the operation of re-setting counter 42 has advanced to close its switch 42 for energizing the right re-setting ends 49 and 48 of upper and lower differential relays 45 and 44, whereby the switch of the upper relay is opened, and the circuit controlled by linear counter switch 43' is placed in readiness for the next operation.

Coordination From the foregoing description of the method of and the illustrated system of devices for controlling the yarn delivery in response to the demand for yarn by the needles to produce a stated number of stitches from a predetermined length of yarn in relatively rapidly operating knitting machines, it will become very clear that the present invention establishes a perfectly automatic coordination between the two factors, that is, the yarn feed and the stitch number, and vice versa, at every moment during the operation of the knitting machine, and facilitates practically instantaneous corrections of even the smallest discrepancies affecting these factors the moment such discrepancies occur.

It will be understood, therefore, that the several diagrammatically illustrated representations of the electrical and mechanical devices employed in the present system are intended to function automatically when the principal knitting factors controlling the evenness, uniformity and other requirements for accomplishing perfection in knitted fabrics are not in absolute balance. Thus either switch 4| of the revolution counter, or switch 43 of the linear counter may operate first to bring these factors quickly into balance.

The ideal situation prevails when both these counter switches are repeatedly operated simultaneously throughout the entire run of the fabric, thus reciprocally cancelling out the functions of the devices controlled by them. That means that the quality of the produced goods is faultless.

Fabric with design or pattern In the foregoing description of coordinating the yarn feed with the demand by the needles for plain, patternless goods, it was stated that the assumed 1,000 stitches of yarn were uniform in length, that is .012 inch long. When it is desired to produce fabrics with designs or patterns, the length of the stitches necessarily must vary. The varying of the stitch length is controlled by the pattern-producing instrumentality such as pattern wheel H5 or its equivalent.

In order to explain the manner in which goods with patterns are produced, let us assume-an exaggerated stitch length for a much reduced number of stitches, as will be hereinafter evident. For the production of a certain desired pattern let us assume that there is employed a successively repeated design produced by a group of three stitches, that stitch group being composed of one stitch an inch long, a second stitch two inches long and a third stitch three inches long. Such group of three stitches constitutes what is known as a repeat. These repeats appear successively throughout the run of the produced fabric, each repeat requiring the indicated six inches of yarn. Four consecutive repeats constitute what is known as a period, and each period, therefore, ,consumes twenty-four inches of yarn, while for five consecutive periods one hundred and twenty inches of yarn would be required.

Inasmuch as each repeat group represents three stitches, and each period four times that number of twelve stitches, five such periods would represent sixty stitches. In other words we assume now, for the sake of elucidation, that for one hundred and twenty inches of yarn only sixty stitches are made by the needles for the production of the required pattern. The assumed length of the three stitches in one repeat is obviously much exaggerated, although such stitch proportion definitely is within the realm of possibility when the present control devices or their equivalents are employed in knitting machines.

Reverting now to the first assumed number of 1,000 stitches for 120 inches of yarn, it may be easily conceived that each repeat of three stitches may be considered within the limits of the combined length of three .012 inch long stitches, or within the total length of .036 inch, but varying in proportions of one to two to three. However, irrespective of the number of stitches and the stitch length, the present invention is intended to automatically correlate the yarn requirements for the production of fabrics having stitches of either uniform length or having groups of stitches of different lengths.

Viewing the present method and system from the practical standpoint in the actual production of knitting fabric, it will be readily seen that this invention is intended to eliminate as much as possible reliance upon human intelligence and operation by the substitution for the heretofore used hand-adjustable devices for correlating the knitting factors of yarn feed and stitch number by automatically functioning instrumentalities, some of which are represented by the predetermining counters. While these counters in themselves are by no means new, their particular employment and their grouping and cooperation in respect to one another in the present system achieve heretofore unknown and most advantageous' results.

Thus when a certain type of knitted fabric is to be produced wherein the amount of yarn required for a stated number of stitches has been ascertained, it is a simple and positive task even for an unskilled person to set the predetermining counters to the required figures. The other mechanisms of the present system controlled by these counters will automatically maintain the predetermined knitting factors in balance throughout the entire run of the fabric.

In consequence of the aforesaid so-to-speak instantaneous and automatic coordination of the principal knitting factors, the yarn feed and the stitch number, and the resulting substantially constant balance maintained between these two factors, the produced knitted fabric will be of a most uniform and even structure throughout its entire length from start to finish, including variations in stitch length produced by the formation of patterns, since not only varying looseness and tightness of stitches and many other faults usually occurring in knitted fabrics produced by the heretofore employed knitting methods are completely eliminated, in short, the present methd and control system assures the production of 10 first grade quality knitted goods of either patternless or plain, or complex patterned construction.

Obviously, the arrangement of the system illustrated, and the various electrical and mechanical devices employed therein are intended for no other purpose except to facilitate the explanation and understanding of the basic principle of the present method. By the same token, the assumed figures of the number of 1,000 stitches to inches of yarn were taken arbitrarily to permit the elucidation of the timing and cooperation between the different devices in the system in accordance with the instant invention.

Thus the specific electrical and mechanical devices illustrated and described are by no means to be considered the only possible solutions for accomplishing the desired results of automatically maintaining the aforementioned principal knitting factors in balance for the purpose of producing faultless knitted fabric, and any suitably designed and correctly arranged means, either electrical or mechanical, or both, which will correlate, synchronize, balance, coordinate or in any other manner automatically control these principal factors to accomplish the results intended to be achieved in accordance with the present method, can be readily substituted.

For example, the entire mechanism for correlating the yarn feed with the stitch number may be completely rearranged by the employment of different types of speed changers, or the pawl releases for freeing one or the other of the ratchet wheels may be operated mechanically, or the ratchet wheels and pawls may be entirely dispensed with and substituted by magnetic clutch devices so arranged that when, for instance, solenoid 3i becomes energized its corresponding clutch device, substituted for ratchet wheel 21 and pawl 28, will become also energized and cause shaft 31 and gear 38 to turn, in response to the movements of bar 30, while the other magnetic clutch device, substituted for ratchet 32 and pawl 33 and controlled by solenoid 36, remains deenergized, and vice versa. Such substitute arrangement being obvious, the same is not illustrated.

In the foregoing description revolution counters 4| and 42 and linear counter 43 were referred to and were shown in the drawings. They are of the make known as Veeder-Root counters, produced by Veeder-Root, Inc., Hartford, Connecticut. It is obvious, however, that any other desired type of pre-settable counters may be substituted, such as, for instance, the Cyclo-Monitor, made by the Counter 8: Control Corporation of Milwaukee, Wisconsin, etc.

Modifications may also be made in the different holding switches for the various circuits, which may take other forms than those shown, or can be actuated in a manner different from that indicated. All of the above suggested variations and substitutions, while not actually illustrated, are evidently readily feasible and can be employed as long as they effect the ultimately desired result of automatically balancing the yarn feed and stitch-producing factors in knitting machines.

It is evident, therefore, that devices which may be readily substituted for those illustrated and described, are to be deemed as residing within the broad scope, intent and principle of the present invention as defined in the annexed claims.

What is claimed as new is:

1. The combination with a Warp knitting machine having at least one warp beam, a bank of knitting needles, and pattern-controlling means, all operated by a cam shaft, of a control system for automatically correlating and balancing the yarn feed from the warp beam in respect to the yarn requirement by the needles and by the pattern-controlling means, said system comprising a primary revolution or stitch counter, a secondary revolution or re-setting counter, and a yarn length measuring counter, all counters being of the predetermining, pre-settable type, said primary and secondary revolution counters being operatively connected with the cam shaft, said yarn length measuring counter being actuated by the yarn moving from the warp beam to the needles; automatically operating yarn feed varying means jointly controlled by said primary revolution counter and said yarn length measuring counter; said secondary revolution counter serving for automatically re-setting said yarn feed varying means to a ready-for-operation state each time said means have completed an operating function of either advancing or reducing the yarn feed in response to the actions of said primary revolution counter or of said yarn length measuring counter, respectively, or vice Versa,

In an automatic yarn feed control system for knitting machines, the latter having at least one warp beam, a bank of needles, a patterncontrolling device; a cam shaft for operating the warp beam, the needles and said device; a speed changer interposed between the cam shaft and the warp beam; a stitch counter and a resetting counter driven by the cam shaft; a linear counter in operative engagement with and actuated by the yarn run-off from the warp beam to the needles; all counters being of the predetermining, pro-settable type; said speed changer having an operative member adapted for movement in two opposite directions, a positive direction, for increasing the speed ofthe warp beam and thereby advancing the yarn feed to the needles, and a negative direction, for reducing the speed of the warp beam and thereby decreasing the rate of yarn delivery to the needles; actuating means for said operative member of the speed changer to move said member in either of its two directions; and a plurality of correlated electrical devices for eiiecting the operation of said actuating means, said electrical devices being connected with and responsive to electric impulses from said counters.

3. In an automatic yarn feed control system for knitting machines, th latter having at least one warp beam, a bank of needles, a cam shaft for operating the warp beam and the needles, and a speed changer interposed between the cam shaft and the warp beam; a stitch counter and a re-setting counter driven by the cam shaft; a linear counter in operative engagement with and actuated by the yarn run-on from the warp beam to the needles, all counters being of the predetermining, pre-settable type; the pre-setting of the stitch and re-setting counters varying in sequence; all of the counters having electric switches adapted to be operated each time the counters have completed the pre-set number of revolutions; said speed changer being adapted to either increase or reduce the speed of the warp beam and having a member for effecting these speed changes when moved in either one or the positive, or the opposite or the negative. direction; electrically actuated means for moving said member of the speed changer in either of its two directions, said means being connected with and being controlled by the switches of said counters, said re-setting counter serving for placing said electrically actuated means to a readyfor-operation state each time said means have completed a function in response to the operation of the switches of either the stitch counter or the linear counter.

4. In an automatic yarn feed control system for knitting machines, the latter having at least one warp beam, a bank of needles, a cam shaft for operating the warp beam and the needles and a speed changer interposed between the cam shaft and the warp beam; a stitch counter and a re-setting counter driven by the came shaft, a linear counter in operative engagement with and actuated by the yarn run-off from the warp beam to the needles, all counters being of the predetermining, pre-settable type; the pre-setting of the stitch and re-setting counters varying in sequence; all of the counters having electric switches adapted to be operated each time the counters have completed the pre-set number of revolutions; said speed changer being adapted to either increase or reduce the speed of the warp beam and having a member for effecting these speed changes when moved in either one or the positive, or the opposite or the negative, direction; said member of the speed changer comprising a pinion; a gear rack engaging the pinion and serving for moving it in either directions; a gear for operating the gear rack; a pair of oppositely operative devices for turning the gear in either one or the other direction; a solenoid and an armature for each of these devices; a differential switch relay for each of the solenoids; the switch-closing relay ends being connected with and controlled by the switches of the stitch and linear counters; the switch-opening ends of the relay being connected with and controlled by the switch of the re-setting counter; auxiliary means for de-energizing the electric circuit of the switch-closing and of one relay while that end of the other relay closes its switch and energizes its respective solenoid for operating one or the gear turning devices in one direction; means for rendering inoperative the other of the gear-turning devices the moment the solenoid of that one gearturning device is energized; and means for de-energizing either of the solenoids upon completion of their function to actuate their respective gear-turning device.

5. The combination with a warp knitting machine having a warp beam, stitch-producing instrumentalities and a cam shaft for operating them, of a system for automatically keeping in predetermined balance the yarn feed from the warp beam with the yarn requirement by these instrumentalities, said system comprising revolution-responsive devices driven by the cam shaft, and at least one device responsive to linear measurements and in operative engagement with the yarn fed from the warp beam, a speed changer interposed between the cam shaft and the warp beam; means for actuating the speed changer for increasing or reducing the speed of the warp beam; and automatic control means for said actuating means connected with and governed by said revolution-responsive and said linear measurement-responsive devices, said speed changer actuating means comprising a speed changer operating element, a member for moving said element in either one of two opposite directions, and elec-r tro-magnetic ratchet and pawl means for. propelling said member in corresponding opposite 13 directions when called up to do so by said automatic control means.

6. The combination with a warp knitting machine having a warp beam, stitch-producing instrumentalities and a cam shaft for operating them, of a system for automatically keeping in predetermined balance the yarn feed from the Warp beam with the yarn requirement by these instrumentalities, said system comprising revolution-responsive devices driven by the cam shaft, and at least one device responsive to linear measurements and in operative engagement with the yarn fed from the warp beam, a speed changer interposed between the cam shaft and the warp beam; means for actuating the speed changer for increasing or reducing the speed of the warp beam; and automatic control means for said actuating means connected with and governed by said revolution-responsive and said linear measurement-responsive devices, said revolution-responsive and yarn measurement-responsive devices comprising predetermining and pre-settable revolution and linear counters provided with switches for closin and opening electric circuits at predetermined intervals, corresponding to the presetting of thes counters, said automatic control means comprising electrically operated electric and mechanical ratchet and pawl devices; and electric circuits connecting said electric devices with the switches of said counters.

7. The combination with a warp knitting machine having a, warp beam, stitch-producing instrumentalities and a cam shaft for operating them, of a system for automatically keeping in predetermined balance the yarn feed from the warp beam with the yarn requirement by these instrumentalities, said system comprising revolution-responsive devices driven by the cam shaft, and at least one device responsive to linear measurements and in operative engagement with the yarn fed from the warp beam, a speed changer interposed between the cam shaft and the warp beam; means for actuating the speed changer for increasing or reducing the speed of the warp beam; and automatic control means for said actuating means connected with and governed by said revolution-responsive and said linear measurementresponsive devices, said revolution-responsive and yarn measurement-responsive devices comprising predetermining and pre-settable revolution and linear counters provided with switches for closing and opening electric circuits at predetermined intervals, corresponding to the pro-setting Of these counters, said automatic control means comprising electrically and mechanically operated devices; electric circuits connecting said electrically operated devices with the switches of said counters; said electrically operated devices including two solenoids for moving said speed changer actuating means in opposite directions, that is, in one or positive direction for increasing the speed of the warp beam, and in the other or negative direction for decreasing the warp beam speed, whenever either one of the revolution counters or said linear counter close their respective switches.

8. The combination with a warp knitting machine having a warp beam, stitch-producing instrumentalities and a cam shaft for operating them, of a system for automatically keeping in predetermined balance the yarn feed from the warp beam with the yarn requirement by these instrumentalities, said system comprising revolution-responsive devices driven by the cam shaft, and at least one device responsive to linear meas- '14 urements and in operative engagement with the yarn fed from the warp beam, a speed changer interposed between the cam shaft and the warp beam; means for actuating the speed changer for increasing or reducing the speed of the warp beam; and automatic control means for said actuating means connected with and governed by said revolution-responsive and said linear measurement-responsive devices, said revolution-responsive and yarn measurement-responsive devices comprising predetermining and pre-settable revolution and linear counters provided with switches for closing and opening electric circuits at predetermined intervals, corresponding to the pre-setting of these counters, said automatic control means comprising electrically operated electric and mechanical devices; electric circuits connecting said electric. devices with the switches of said counters; said speed changer actuating means comprising two connected parts adapted for movement in opposite directions, that is, a positive, speed-increasing and a negative speed reducing direction; said electrically operated devices comprising two solenoids, one for each of said speed changer actuating parts; a pair of differential relays with switches for closing and opening the solenoid circuits, the switch-closing end of one relay for one solenoid being connected with and controlled by the switch of one of the revolution counters, the switch-closing end of the other relay for the other solenoid being connected with and controlled by the switch of the linear counter; the switch-opening ends of both relays being connected with and controlled by the other revolution counter; the system including means for automatically de-energizing one of the solenoid circuits when the other solenoid circuit becomes energized and moves its corresponding speed changer actuating part; and automatically operable means for releasing one of the speed changer actuating parts when the other part is being moved by its respective solenoid.

9. In a system for producing fabric of a uniform structure on a knitting machine, the latter having a cam shaft and at least one warp beam, at least two revolution-responsive devices driven by the cam shaft and at least one linear measurement-responsive vdevice operatively associated with the yarn delivered from the warp beam, said revolution-responsive and linear measurementresponsive devices being electrically connected with one another, and electrically operated relay means interposed between, electrically connected with and governed by these devices for reciprocally controlling their respective operation, and electro-magnetically operated mechanical means automatically actuated by the functions of these devices, and a speed changer operative by said mechanical means and operatively connected with the warp beam and serving for governing the yarn feed. and correlating it with the yarn demand by the fabric-producing instrumentalities.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,030,425 Beniston et a1 Feb. 11, 1936 2,298,888 Kaufmann Oct. 13, 1942 2,361,526 Bassist Oct. 31, 1944 2,423,105 Lambach July 1, 1947 2,486,525 Fuhrer et a1 Nov. 1, 1949 2,539,296 Clentimack Jan. 23, 1951 2,541,192 Blake Feb. 13, 1951 2,600,256 Morrison et a1 June 10, 1952 

